| 摘要 |
PURPOSE:To obtain the composite material with both high mechanical strength and toughness, excellent in high-temperature characteristics and the resistance to welding with aluminum alloys. CONSTITUTION:This composite material is so designed that 3-30vol.% of SiC <=500nm in particle diameter and 5-10vol% of Co, Ni and/or Ti metallic powder are dispersed in the inside or boundary of the crystal grains 0.3-5mum in average particle diameter of the matrix of a boride of one element selected from groups 4a and 6a elements. This composite material can be obtained by molding a mixture of a boride, SiC and metallic powder followed by sintering in a vacuum or inert atmosphere at >=1300 deg.C. By this method, the composite material has such a special texture that SiC fine particles and the metallic powder each of nano size have been dispersed in the boride matrix, being significantly high in breaking strength and breaking toughness, etc. In cutting aluminum alloys, this composite material has cutting characteristics better than those of carbide alloys, being more inexpensive than diamond sintered compacts. Even in the case of a jig material for producing aluminum cans, this composite material is lighter than carbide alloys and presents high durability compared to them. |
